The present invention is directed to an emergency breathing apparatus incorporating a container system for pressurized fluids that is lightweight and flexible.
There are many applications for a portable supply of fluid under pressure. For example, SCUBA divers and firefighters use portable, pressurized oxygen supplies incorporated into emergency breathing apparatuses. Commercial aircraft employ emergency oxygen delivery systems that are used during sudden and unexpected cabin depressurization. Military aircraft typically require supplemental oxygen supply systems as well. Such systems are supplied by portable pressurized canisters. In the medical field, gas delivery systems are provided to administer medicinal gas, such as oxygen, to a patient undergoing respiratory therapy. Supplemental oxygen delivery systems are used by patients that benefit from receiving and breathing oxygen from an oxygen supply source to supplement atmospheric oxygen breathed by the patient. For such requirements, a compact, portable supplemental oxygen delivery system is useful in a wide variety of contexts, including hospital, home care, and ambulatory settings.
High-pressure supplemental oxygen delivery systems typically include a cylinder or tank containing oxygen gas at a pressure of up to 3,000 psi. A pressure regulator is used in a high-pressure oxygen delivery system to xe2x80x9cstep downxe2x80x9d the pressure of oxygen gas to a lower pressure (e.g., 20 to 50 psi) suitable for use in an oxygen delivery apparatus used by a person breathing the supplemental oxygen.
In supplemental oxygen delivery systems, and in other applications employing portable supplies of pressurized gas, containers used for the storage and use of compressed fluids, and particularly gases, generally take the form of cylindrical metal bottles that may be wound with reinforcing materials to withstand high fluid pressures. Such storage containers are expensive to manufacture, inherently heavy, bulky, inflexible, and prone to violent and explosive fragmentation upon rupture. Employing such containers to an emergency breathing apparatus so as to provide an ambulatory supply of oxygen can add significant undesired weight and bulk to the apparatus.
Emergency breathing apparatuses are often used on military ships (surface and submarine) where they are stowed in various locations throughout the ship so as to be available in the event of an emergency to any personnel in the vicinity. Stowing such devices throughout the ship, for example hanging them from bulkheads, takes up space within the ship which is typically already scarce, especially in smaller submarines. Accordingly, it would be desirable to replace the conventional emergency breathing apparatuses which employ oxygen canisters with a device employing a smaller, more compact oxygen storage vessel.
Furthermore, conventional emergency breathing apparatuses employing oxygen canisters are rather heavy, each weighing in the vicinity of 15 pounds. Thus, it would also be desirable to replace the conventional emergency breathing apparatuses which employ oxygen canisters with a device employing a more light weight oxygen storage vessel.
Container systems made from lightweight synthetic materials have been proposed. Scholley, in U.S. Pat. Nos. 4,932,403; 5,036,845; and 5,127,399, describes a flexible and portable container for compressed gases which comprises a series of elongated, substantially cylindrical chambers arranged in a parallel configuration and interconnected by narrow, bent conduits and attached to the back of a vest that can be worn by a person. The container includes a liner, which may be formed of a synthetic material such as nylon, polyethylene, polypropylene, polyurethane, tetrafluoroethylene, or polyester. The liner is covered with a high-strength reinforcing fiber, such as a high-strength braid or winding of a reinforcing material such as Kevlar(copyright) aramid fiber, and a protective coating of a material, such as polyurethane, covers the reinforcing fiber.
The design described in the Scholley patents suffers a number of shortcomings which makes it impractical for use as a container for fluids stored at the pressure levels typically seen in portable fluid delivery systems such as SCUBA gear, firefighter""s oxygen systems, emergency oxygen systems, and medicinal oxygen systems. The elongated, generally cylindrical shape of the separate storage chambers does not provide an effective structure for containing highly-pressurized fluids. Moreover, such large containers cannot be easily incorporated onto an emergency breathing apparatus. Also, the relatively large volume of the storage sections creates an unsafe system subject to possible violent rupture due to the kinetic energy of the relatively large volume of pressurized fluid stored in each chamber.
Accordingly, there is a need for improved container systems made of light weight polymeric material and which are robust and less susceptible to violent rupture and can be easily incorporated into an emergency breathing apparatus without adding significant weight or bulk.
In accordance with aspects of the present invention, an emergency breathing apparatus includes a gas storage pack that is robust, unobtrusive, and light weight. More particularly, the present invention encompasses an emergency breathing apparatus comprising, a hood adapted to be worn over the head of a person, a gas storage pack, and a supply conduit connecting the hood to the gas storage pack. The gas storage pack includes a pressure vessel for containing a supply of a breathable gas. The pressure vessel comprises a plurality of hollow chambers, each having a substantially spherical or ellipsoidal shape, a plurality of relatively narrow conduit sections, each being positioned between adjacent hollow chambers to interconnect the hollow chambers, and a reinforcing filament wrapped around the hollow chambers and the conduit sections. The gas storage pack further comprises a gas transfer control system attached to the pressure vessel and constructed and arranged to control flow of gas into and out of the pressure vessel and a housing for containing the pressure vessel.
Other objects, features, and characteristics of the present invention will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of the specification, and wherein like reference numerals designate corresponding parts in the various figures.